Natsumi wants to become a photographer. She takes a bike which her late father left behind and goes to a forest to find a firefly she saw with her father. In the forest, Natsumi meets old mother Yasu and old son Jizo. They run a general store. Natsumi learns how to live in nature from them. She has happy summer days there. One day, Jizo tells her that he became estranged from his son in the past.
Unfortunately the movie Natsumi's Firefly is not yet available on HBO Max.
| Camera | Yasushi Hanamura | Director of Photography |
| Sound | Akira Fukada | Sound |
| Writing | Akio Morisawa | Writer |
| Writing | Shôen Kataoka | Screenplay |
| Directing | Ryuichi Hiroki | Director |
| Editing | Jun'ichi Kikuchi | Editor |
| Crew | Tomoko Oshida | Script |
| Directing | Yoichi Nakzato | Assistant Director |
| Production | Yasushi Minatoya | Line Producer |
| Costume & Make-Up | Michiko Nagae | Makeup & Hair |
| Production | Yasushi Utagawa | Co-Producer |
| Sound | Uru | Theme Song Performance |
| Sound | Eiko Ishibashi | Original Music Composer |
| Writing | Sho Kataoka | Screenplay |
| Writing | Takehiko Minato | Screenplay |
| Art | Tomoyuki Maruo | Production Design |
| Sound | Akira Fukada | Sound Recordist |
| Sound | Toshihiro Sugita | Music Producer |
| Visual Effects | Hajime Matsumoto | Visual Effects |
